My apologies, but I'm not sure what you mean by "trigger belt"; my British->American translator book is misplaced
If this is the serpentine belt, I just had mine replace about 10000 miles ago, and I just rolled over to 60,000 miles. The mechanic told me it was in very bad shape and would have failed soon had he not caught it (the car was in for other repairs).
For an OBD-II tool, go to
http://www.obd-2.com 
